著者

富山 眞吾 梅田 浩司 花室 孝広 高島 勲 林 信太郎 根岸 義光 増留 由起子

出版者

一般社団法人 日本鉱物科学会

雑誌

岩石鉱物科学 (ISSN:1345630X)

巻号頁・発行日

vol.36, no.4, pp.111-121, 2007 (Released:2007-11-29)

参考文献数

15

被引用文献数

1 2

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Mutsu-Hiuchidake Volcano has an erosion caldera which shows a horseshoe-like geomorphological feature toward east. Tertiary strata as a basement are distributed in the caldera. Tertialy strata and a part of pyroclastic deposits of the Mutsu-Hiuchidake Volcano have altered strongly to moderately by hydrothermal activities related to the volcanism. This study is to clarify a progress history of the alteration by using a geological mapping, thermoluminescence (TL) dating, x-ray diffraction analysis, an infrared reflection absorption analysis and a fluid inclusion study.      Highly altered zone is recognized in the area of midstream to upstream along the Ohakagawa and the Koakagawa within erosion caldera. The argillic alteration zone surround a silicification zone in the highly altered area shows a circular distribution. The strongly altered areas are along NNW-SSE to NNE-SSW fractures. The alteration areas were divided into the smectite, kaolinite, alunite and pyrophyllite zones.      The kaolinite and alunite zones give the TL ages of quartz 67 ± 13 ka (KG-5), 88 ± 18 ka (OG-4) and 91 ± 23 ka (OG-1). The smectite zone within the argillic alteration zone of outside of collapse caldera, yield the ages 752 ± 215 ka (SO-2) and 615 ± 197 ka (KG-1). These TL ages suggest the hydrothermal activity end at 70 to 90 ka.      The existence of pyrophyllite suggests that hydrothermal temperatures were 200 to 250 °C in these area. This is supported from the homogenization temperatures of fluid inclusions in calcite, 242 °C in average.

著者

富山 眞吾 上田 晃 北井 亜希子 葵 守一

出版者

公益社団法人 日本分析化学会

雑誌

分析化学 (ISSN:05251931)

巻号頁・発行日

vol.60, no.2, pp.131-142, 2011 (Released:2011-04-01)

参考文献数

31

被引用文献数

4 5 2

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食品原材料となる地下水の品質管理の問題が起きており,地下水の起源について水質特徴などの科学的根拠に基づいて判別する技術が必要とされている.本研究は,埼玉県狭山市にある株式会社フードケミファ新埼玉工場の井戸で採水している地下水と周辺河川水を対象に,水素・酸素安定同位体比等の地球化学的手法と3次元数値モデルによる地下水流動解析を用いて地下水の起源や流れを予測した.地下水の水質は関東平野西縁辺部の河川水と同様の重炭酸カルシウム型であり,河川水と比較してNa+とHCO3−に富む傾向にある.水素・酸素同位体比から,地下水の起源は入間川上流等の平野縁辺の河川にあることが推定される.数値モデルによる地下水流動解析では入間川上流域から新埼玉工場に向かう地下水の流れが予測され,主要陽・陰イオン濃度や水素・酸素安定同位体比から推定される地下水流動と整合的である.地球化学的手法と数値解析により得られた結果は従来の知見と矛盾せず,地下水起源の判別法としての可能性が示唆された.

著者

萩野 翼 富山 眞吾 五十嵐 敏文

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.137, no.2, pp.24-35, 2021-02-28 (Released:2021-02-26)

参考文献数

46

被引用文献数

2

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This study involved a mine in Akita Prefecture, Japan, which was closed in the 1970s and from which acid mine drainage (AMD) flows directly into a nearby river. Local residents use river water downstream of the mine, at a point-of-use, for agricultural purposes. In selecting factors to be used as a contribution index, the flow rate at multiple points including tributaries, and the concentrations of dissolved ions and heavy metals, were measured periodically and their trends evaluated. The river flow rate increases with rainfall, the AMD flow increases during the snowmelt season. These two periods and the river low-flow period were selected for study. Mine drainage is acidic (pH 3.0-3.6), and comprises Mg-SO4 type water quality throughout the year, with higher concentrations of SO42-, S-Fe, Cu, and Zn than those of river water. Downstream of the mine, where the AMD merges, the concentrations of heavy metals gradually decreased with increasing distance downstream, particularly during the low-flow period. The SO42- fluxes did not change from above to below the AMD merge-point, and the heavy metals fluxes decreased after merging in the order S-Fe > Cu > Zn. As for the factors that decrease the concentration and fluxes, the possibility is considered that S-Fe has an effect of oxidizing and precipitating Fe2+ due to the increase in pH by the mixing with river water and dissolved oxygen. And Cu, Zn has an effect of adsorption accompanying the formation of surface complex of iron precipitates. The AMD contains high concentrations (320-400 mg L-1) of SO42- due to the acidification of pyrite, and no precipitation of heavy metals was observed in the stream. Since precipitation phenomena such as heavy metals are not recognized in SO42-, an index indicating the degree of impact of AMD on the water quality of the point-of-use was calculated using SO42- as a contribution ratio; CR. The CR of the AMD to water quality at the point-of-use is in the range of 2%-12%.

著者

富山 眞吾 五十嵐 敏文 井伊 博行 髙野 日出男

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.132, no.5, pp.80-88, 2016-05-01 (Released:2016-05-14)

参考文献数

30

被引用文献数

6

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The understanding of source and flow path of the groundwater provides important strategy for the environmental management of mines. Thus, groundwater samples from the shaft and level in the Shimokawa mine and the surrounding river water samples were taken and the stable isotopes of hydrogen and oxygen and water quality of the samples were analyzed. The results indicate that shallow groundwater starts mainly from mountain-sides and passes through rocks above ore bodies. The simulation of groundwater flow was also conducted. The distribution of velocity vector of the simulated result showed that down streamlines which flows more than 2×10-3 m per day from mountain-sides to the ore bodies were observed. By considering the altitudes of mountain-sides range from 300 to 550 m, these results correspond well with the altitudes estimated from δD and δ18O values of samples.

著者

富山 眞吾 井伊 博行 小泉 由起子 目次 英哉

出版者

公益社団法人 日本地下水学会

雑誌

地下水学会誌 (ISSN:09134182)

巻号頁・発行日

vol.52, no.3, pp.261-274, 2010 (Released:2012-02-01)

参考文献数

14

被引用文献数

2 6

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休廃止鉱山である宮崎県富高鉱山では、砒素を含む坑内水が未処理のまま河川へ排水されており、将来的な対策として中和処理が検討されている。地表踏査やボーリング調査、鉱山の既存情報から、梅ヒ断層及び二坑ヒ断層に挟まれた区域では高透水性領域が形成されていることが想定される。大王山斜面から涵養した降水は高透水性領域の不飽和部を経て地下水面に達した後、地形的に低い周囲の河川へ流動しているものと考えられる。概念モデルをベースに数値モデルを構築し、降雨と坑内水流量及び地下水位との応答再現を試みた。その結果、おおよそ実測値と整合的な計算結果が得られ、概念モデルの妥当性を示すものと評価できる。